The Study Of Adaptive Equalization Based On Variable Step-size Algorithm

One factor which effects data transmission is the intersymbol interference (ISI).The reason of ISI is the characteristic of a non-ideal channel Adaptive equalization is mainly solution of dealing with ISI.Adaptive equalization is a pivotal technique in solving ISI, which can track changes of channel parameters adaptively, modify weights value ceaselessly, consequently, can achieve objective of removing ISI.This paper discusses and simulated analyze several kind of equalization techniques, as well as optimizing traditional LMS algorithm by using Sigmoid and Kei tongue-line function.Also, I make use of Matlab to simulated analyze general channel and telephone channel for the improved adaptive equalization algorithm. Result and traditional LMS algorithm is compared in the same transmission channel about convergence speed and steady-state error. As a result, improved algorithm effectively improves the function of the convergence rate and recede steady-state error. Major work in the following points:1. Analyzing the normal algorithms of LMS and simulating these two algorithms with Matlab in 8PAM,4PAM.2. Based on the fundamental of adaptive equalization and study actuality, this paper introduces the typical adaptive equalization algorithms and some questions consist in them. Furthermore, ground on above typical adaptive equalization alg-orithms, this paper proposes two imp-roved algorithms3. Simulinking this improved algorithm and giving the result of it.The simulation results show: the equalized performance of them achieves great improvement compare with the conventional algorithms.